Template:Pagelang/doc
This is a documentation subpage for Template:Pagelang. It contains usage information, categories and other content that is not part of the original Template page. |
This template is used on approximately 50,000 pages. To avoid large-scale disruption and unnecessary server load, any changes to this template should first be tested in its /sandbox or /testcases subpages or in your own user subpage. The tested changes can then be added to this page in one single edit. Please consider discussing any changes on the talk page before implementing them. |
Uses Lua: |
Usage
editThis stuff template for check language of translated subpage (for translatable pages). Used for automate substitution localized values that will match the language of the current page. Also used to help defining text direction (with using with {{dir}}). It is designed to be called from other templates.
Parameter | Description | Type | Status | |
---|---|---|---|---|
Page title | 1 | Page title to get language for. By default the title of the current page. | Page name | optional |
Examples
edit{{Pagelang}}
{{Pagelang|Page name}}
{{Pagelang|Page name/ja}}
ja
Examples of common use in translated pages or templates:
<!--
Display the language name of the given the language code in parameter 1, in the same language as the current translated page with a tooltip showing the language name in the user's preferred language.
--><span lang="{{#bcp47:{{int:lang}}}}" title="{{#language:{{1}}|{{int:lang}}}} ({{{1}}})"><!--
--><span lang="{{#bcp47:{{pagelang}}}}" dir="{{#dir:{{pagelang}}}}" class="autonym"><!--
-->{{#language:{{1}}|{{pagelang}}<!--
--></span></span>
<!--
Align the floatting image to the correct side, depending on the language of the current translated page
-->[[File:Example|{{dir|{{pagelang}}|left|right}}|30x30px]]
Technical note
editWhen a subpage page contains any (single or double) quotes or ampersands, it is not a valid language code; PAGENAME
and SUBPAGENAME
normally HTML-encodes these characters in their return value, so they are safe to use as input of #language
. But #titleparts
restores these quotes or ampersands by HTML-decoding them.
But then {{#language:}}
will produce a fatal server error when it is used with "language codes" with single quotes.
- Proof
This still works:
{{#language:fr|{{#titleparts:There's a fatal bug in MediaWiki|1}}}}
This does not work either:
{{#language:fr|{{PAGENAME:There's a fatal bug in MediaWiki}}}}
Nor does this:
{{#language:fr|There's a fatal bug in MediaWiki}}
This is a critical bug of the {{#language:}}
parser function, and apparently a severe security issues that could be caused by some clever insertion of code in PHP after the quote.
This bug only occurs in the second parameter of {{#language:}}
(the target language into which to give the name of the language specified by the code in the first parameter). Only the first parameter is checked for validity, but not the second one. Here, where {{#language:}}
cannot find the name of the language, in any target language, it should return the native language name, as in:
{{#language:fr|invalid language}}
- français
- Work-around used in this template
To avoid this severe bug, we want to detect quotes (or ampersands) in subpage names, as they are invalid anyway in any language code, in order to return an empty string and not the subpage name: such subpage name cannot be a language code anyway.
One way to detect subpages that cannot be safe language codes is to check if their value filtered by {{#titleparts:}}
is equal to their value filtered by {{PAGENAME}}
: if they aren't equal that's because they contained "ampersands", or quotes.
- Why we use
{{#titleparts:}}
and not just{{SUBPAGENAME}}
?
{{#titleparts:}}
is used in this template instead of using {{SUBPAGENAME}}
, but using SUBPAGENAME
would not avoid the bug either, because it could as well return the full page name containing the quotes ({{SUBPAGENAME}}
only works in namespaces where subpages have been activated, so it does not work in the main namespace to see if it has been translated using a language code suffix).
See also
edit- Manual:PAGENAMEE encoding
- {{TNT }}
- {{LL }}
- {{BCP47 }}
- {{Dir }}